This is a totally weird self serving project that quite frankly just shows what happens when the frantic gears spin out of control in my bored little brain. Nothing you see here was born out of necessity, nor does it fill a niche that needed filling. And most likely there will be those that will scratch their head and wonder WTF is this good for! And for those devoted Atari hardware preservationist, I'll warn you now that 1050's will die before this project is done (and many more, if this spreads). So if you can't stomach the thought of that, it's best that you stop reading this immediately, curl up into a little ball, and pretend the world is sane.

Are you still here?

Good, let's proceed.

As some of you may already know, this all began a few days ago when I proposed putting a 1088XEL motherboard into a 1050 floppy drive case.

Well that was going to get very messy real fast, with lots of wires and dangling bits holding it all together. So like any reasonable and somewhat lazy person would probably conclude "I decided no way was I going to do that!" But the idea wouldn't die. And to add fuel to this, a posting in a PM suggested designing a new motherboard for a few dead 1050s they had laying around gathering dust. Stupid me latched onto 'new motherboard', and at first I thought that was totally crazy, after all I just finished a big project like that earlier this year, and I just wasn't feeling it. Little did I realize that they weren't on the same wavelength as me, and were really talking about a custom XF drive board that would fit into a 1050 case. Not a bad idea in itself, but that's a whole different story, for an entirely different thread.

Anyway the gears kept turning, and I thought that would be kinda cool and somewhat awesome to have a A8 computer motherboard that would drop into a 1050 case, with no, or very little modification. And even better still if it could piggyback on the 1088XEL project with an internal CF drive that could utilize flashjazzcat's 1088/U1MB Bios to make that CF drive really purr.

I started getting excited, and the ideas just came pouring forth, a dangerous phenomena to say the least . So suffice it to say a new alternative motherboard project was born.

Please welcome the 1088XLD

1088 - Total amount of RAM memory due to built-in U1MB.XL - Because we are packaging this in a 1050 case, it'll take on the style of this iconic series.D - Just like the 1450XLD it'll sport an internal drive, although a much faster and more capable solid state one.

Obviously I have a long ways to go. But it's a good start, and since it will re-purpose a lot of the 1088XEL design, it should go much more smoothly through the development process.

PCB Image UPDATED On August 8th 2018, now much closer to final layout

Features

U1MB

UAV (routed to standard DIN-5 rear panel video jack)

Will support PAL or NTSC configurations

Integrated XEL-CF3 electronics (will leave MPBI+ expansion bus free)

Rapidus, VBXE, and P-Covox interface control signals to be provided by independent header

However, heads up on the UAV - Bryan is out of them and not planning another run that I'm aware of. I think mentioned something about a new Rev E or a whole new design, one that would also offer audio out for use in 400s, 5200s, 7800s, etc. Not sure if he's firmed up those plans or not though.

Yep Bryan mentioned that to me on my last UAV order, but I've got 4 or 5 in stock which will easily get me by for quite sometime, especially since this project probably won't even go to a PCB house until the end of the year.

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So just a heads up. Since the 1050 comes with two SIO ports I opted to not integrate an SIO2PC, and instead will be going with an external one like the one Lotharek makes (got 3 of those). Other than that small omission, the 1088XLD will come with everything that the 1088XEL has except for the following...

Doing the same with an 810 would offer more room for expansion... and leave room for a half-height 5-1/4" floppy drive if a custom front panel was created.

True, but I've never been a big fan of the 810's looks. Plus it would take up more desk space then I like. But I could see it being another way to go, especially if you want an integrated floppy drive.

Obviously I have a lot of components left to drop into the layout. And that will happen in due time, but I really should conjure up the schematics first before I take the layout much further.

I just needed to see how the big items might fit, and to get a feel for the land so to speak. On the plus side, there's a lot more breathing room with this footprint vs. the 1088XEL, but things will likely be tight on the front panel that will be replacing the original floppy drive mechanism. I'm looking at some changes to the TK-II chip to better accommodate that. First off, I'll give up the 2nd PS/2 keyboard port which will give me back two I/O pins on the PIC chip. Those can then take the place of physical switches (swap button and mouse port select). I can then use the 'Windows' and the 'App' keys to control those aspects. So it will require an XLD version of the TK-II firmware, but it will free up space on the front panel in the process.

You can 3d pint a 1050 case... .... I've seen some 3d printed face plates too...

I've never seen something 3D printed at this size that looks anywhere near as good as injection molded plastics, not unless it's done professionally which would still cost bucks, although no where near as much as creating the molds for injection. However a lot of people probably have or know where they can get dead 1050s (I have 3), so that looks like the better option at least for me .

On a side note, a dead 1050 also brings the required SIO connectors with it.

I've never seen something 3D printed at this size that looks anywhere near as good as injection molded plastics, not unless it's done professionally which would still cost bucks, although no where near as much as creating the molds for injection. However a lot of people probably have or know where they can get dead 1050s (I have 3), so that looks like the better option at least for me .

On a side note, a dead 1050 also brings the required SIO connectors with it.

I actually have one of these but have never used it ! I funded the kickstarter, got less into 3d printing by the time it was shipped, and when it arrived it went into the black hole (my wife calls it the garage, but we all know what it is).

At some point, I really ought to get my act together and at least try it out

Nice printer, and a cool idea with the acetone vapor polishing, but still not the same look of a stock Atari XL peripheral case. I'm just not into glossy plastic, but if it could do a brushed metal look, I'd be sold!

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So here are the parts you want to keep and reuse from the original 1050 motherboard.

I was also kicking around the idea of reusing the 6532 RIOT chip, but unfortunately it's a 1 Mhz version. It could have been mapped into an unused area of memory and given us an extra 16 bits of latched I/O and 128 bytes of RAM. Oh well .

Wait maybe I could build in a 2600 mode using that part . Just kidding . Although truthfully both the 6507 CPU and RIOT chip would give you a good start at that.

If anyone sees something useful to be added, I can substitute whatever signal that may be for some of the extra GNDs.

Not sure what 'M1', VB and '/CI' are ? Maybe they perform something similar to some of the below ?

If you want cartridges to be able to be plugged into the thing that plugs into the MPBI+, you'll need S4,S5, RD4 and RD5.

I see /EXT but I'm not sure if it's /EXTSEL or EXTENB. EXTENB would be nice, but /EXTSEL is needed for the PBI to work well.

I don't see /REF, which is useful for pretending to be Antic and possibly taking over the bus. It's possible that /HALT might be sufficient for that, but the Antic schematics are different for the two pins, and I'm not sure if /HALT will work the same way.

That's an interesting idea. Didn't the designer of the Supercolor card get permission to do that recently? Though both the UAV and the Supercolor card use SMD components to save space and cost, don't they?

Not sure. But the UAV can't have a lot of components on the PCB as it's kinda tiny. So integrating it shouldn't be that hard for an electronics guy like Michael. And since the UAV kinda replaces some original parts, which if I understood correctly become useless when installing a UAV, Michael would save some extra parts (plus the headers/sockets he'd need to piggyback the UAV onto the new motherboard) and therefor some space on the new MB.